V,
Iron Vest and Iron Palm have become uncommon and rare in the world of firearms and other weapons. They are hard to do, boring, and eat so much of your free time that they almost seem not worth it for many people.
The herbs one uses are not that rare. Though the processes you need to create such an internal pill can be. Certain herbs must be cooked in wine, then sun dried. Others need to fried in vinegar then wine, then dried. Others need to be cooked in ginger juice and or baby urine( I kid you not). Then you grind them up add them to boiling honey and then make pills that you take for the first 3 months when you are starting the program. The version I learned has no hitting only a lengthy qi gong set, that terminates in sitting meditation to run the qi and then a special belt is used to help aid the organs to learn to seat themselves under the ribcage.
I agree with others that certain people should never learn these skills to cause harm to others. But the strength benefits outweigh the destructive damage you can learn.
Hope your training and your shifu and kwoon are well.
Peace,
Dale
Mouth Boxers have not the testicular nor the spinal fortitude to be known.
Hence they hide rather than be known as adults.